Acceptability of 11 fortified balanced energy‐protein supplements for pregnant women in Nepal

Abstract Evidence suggests that multiple micronutrient and balanced energy protein (BEP) supplementation during pregnancy can decrease the risk of stillbirth and small‐for‐gestational‐age births and increase birth weight. We conducted a mixed‐methods formative research study to identify the most acceptable among a range of 11 candidates fortified BEP supplements for use in pregnancy and lactation in a rural district in Nepal. Forty pregnant women aged 15–40 years participated in a test meal tasting of 11 different sweet and savoury candidate BEP supplements. Each participant rated the products on organoleptic properties using a 7‐point hedonic scale (1 = Dislike it very much to 7 = Like it very much), ranked her ‘top 3’ most liked supplements, and subsequently discussed each product with peers in focus group discussions (FGDs). Five supplements (sweet lipid‐based nutrient supplement (LNS), savoury LNS, sweet vanilla biscuits, vanilla instant drinks and seasoned pillows) achieved the maximum overall median hedonic score of 7, with sweet LNS and seasoned pillows ranking as the top 2. This was consistent with the assessments in FGDs. Women in the FGDs expressed dislike of the smell and taste of the cocoa drink, savoury masala bar, sweet mango bar and savoury curry biscuit, which was consistent with the hedonic scale scores. This study provides valuable insights into our understanding of women's acceptance of different BEP supplements during pregnancy in rural Nepal and has helped identify the two most accepted BEP supplements to be used in a two‐month home trial to assess utilisation and compliance in this setting.


| INTRODUCTION
Maternal undernutrition is highly prevalent in low and middle-income countries (LMICs) where the increased nutritional requirements during pregnancy are often unmet through traditional diets (S. E. . The first 1000 days of a child's life, from conception until the child's second birthday, is a critical period to lay the foundations for optimal child health, growth and development. The nutritional status of the mother and child during this time can have a profound impact on a child's ability to grow, learn and thrive (Martorell, 2017).
It was estimated that in 2015, one in seven newborns, or 20.5 million babies globally, were born low birth weight (LBW); 48% of these were born in South Asia and 24% in sub-Saharan Africa (Blencowe et al., 2019). The average annual risk reduction (AARR) has stalled in the past decade to only 1% (Blencowe et al., 2019). The 2025 World Health Assembly target to reduce prevalence of LBW by 30% will be unattainable unless the AARR is tripled to 2.7%, and so there is more need now than ever to better understand the potential for interventions towards reaching these global targets (United Nations, 2015). The high burden of LBW is biologically linked to the high burden of maternal undernutrition. Undernourished women in many LMICs enter pregnancy with low nutritional reserves; an estimated 240 million are underweight (body mass index [BMI] < 18.5;Di Cesare et al., 2016). Low maternal BMI and short stature are associated with increased risks of a variety of adverse reproductive outcomes including preterm birth and small for gestational age (SGA), the two underlying causes of LBW (Kozuki et al., 2015; A. C. C. Rahman et al., 2015).
One potential nutritional intervention is the current recommendation made by the World Health Organization (WHO) in the 2016 antenatal care guidelines to provide BEP dietary supplementation in undernourished populations (WHO, 2016). This recommendation is based on findings from systematic reviews of BEP supplementation during pregnancy that demonstrate moderate levels of evidence that such dietary supplementation can decrease the risk of stillbirth and SGA births and increase birth weight (Imdad & Bhutta, 2011;Ota et al., 2015;Stevens et al., 2015). The systematic reviews of existing BEP trials, however, showed that the studies used a wide range of BEP supplements, which differed in energy content, nutritional composition and forms (Bill & Melinda Gates Foundation, 2017). In 2016, The Bill & Melinda Gates Foundation (BMGF) convened an expert group to recommend the optimal nutritional composition of a BEP supplement for use in pregnant and lactating women (PLW) in low income and food insecure contexts (Bill & Melinda Gates Foundation, 2017). Before implementing the randomised controlled trial (RCT) designed to test the efficacy of the BEP supplement(s) during pregnancy and lactation on pregnancy and child health outcomes in rural Nepal (ClinicalTrials.gov Identifier: NCT03668977), it is important to first identify which of the BEP supplements is well accepted by the participants in the study area.
To optimise effectiveness, the BEP supplement to be used in the RCT must be consumed on a daily basis throughout pregnancy by those in the intervention group. Sensory characteristics of food such as taste, texture, smell and appearance have distinct and influential effects on food acceptability (Piqueras-Fiszman & Spence, 2015). On the individual level, complaints about the sensory properties of the supplements, particularly during pregnancy, are known to influence adherence as seen in many studies (Clermont et al., 2018;Harding et al., 2017;Klevor et al., 2016;Lutsey et al., 2008;Young et al., 2010). The hedonic scale (quantitively collected) is a widely used method for quantitatively measuring consumers' experienced quality of food (i.e., liking and acceptability; Lawless & Heymann, 2010). Personal factors such as values, beliefs, attitudes and demographics as well as situational factors like meal preparation, consumption situation, context and environment can influence food quality perceptions (Furst et al., 1996). Qualitative methods such as observations, in-depth interviews and focus group discussions (FGDs) are commonly used to understand the contextual factors influencing quality perceptions. A mixed approach of quantitative and qualitative methods is commonly applied to obtain detailed and nuanced information concerning factors that could affect the acceptability of supplements as evident in several acceptability of nutritional supplements studies among PLW in low-income countries (Clermont et al., 2018;Harding et al., 2017;Isanaka et al., 2019;Jones et al., 2021;Klevor et al., 2016;Young et al., 2015).
The objective of this present study was to identify the two most preferable BEP supplements among a larger group of 11 supplements specifically produced for use in pregnancy and lactation in the South Asian context for this study. In this study, we discuss the mixedmethods design used to shortlist the most accepted BEP supplements among pregnant women and triangulate the quantitative and qualitative findings to discuss the facilitating factors and barriers to appropriate utilisation of the supplements.

| BEP supplements
To meet the nutritional needs of pregnant women in rural Nepal, 11 BEP supplements were developed in different flavours and forms

Key messages
• Understanding the acceptability of balanced energy protein supplements by pregnant women along with the potential facilitators and barriers to their use is vital to ensure regular consumption and compliance.
• Pregnant women in rural Nepal liked both the sweet and savoury products and suggested having the option to choose from more than one type of product would facilitate its daily consumption throughout pregnancy.
• Concerns regarding the cost of the supplements, strong aversion to smell/taste of certain supplements, and the inability to eat the supplement in private were some of the deterrents for possibly not being able to eat the supplement daily specifically for this study according to the BMGF guidelines (Bill & Melinda Gates Foundation, 2017). Nine of the BEP supplements were developed in collaboration with Nutriset S.A.S. in France and two were developed in collaboration with MARS Incorporated in India.
Out of the 11 BEP supplements, six were characterised as sweet and five as savoury. The 'sweet' products were not excessively sweet but sweeter in comparison to the savoury products. The added sugar in the sweet products ranged from 11.4 to 21.6 g per 100 g serving for the sweet products and 0.0 to 5.1 g for the savoury products (Table S1). Each BEP supplement's nutrient content was either already in line with the guidance for the macro-and micronutrient content developed by the experts' consultation meeting organised by the BMGF or was close and could be brought fully in line if selected (Bill & Melinda Gates Foundation, 2017). The nutrient composition of each of the 11 BEP supplements is presented in Table 1.

| Study overview
The current study was the first of two phases of formative research designed to inform which BEP supplements among the 11 forms, types and flavours were the most acceptable in the South Asian context. This first phase was a single-meal test that aimed to collect data to describe the general preferences/acceptability across different BEP supplement types and flavours and salient facilitating or constraining factors related to the use of each. Results from the first phase would identify a small number of BEP supplements for an 8-week home-tasting pilot trial (second phase). The shortlisted BEP supplements found to be most acceptable and utilised from this formative research would then be used in a larger randomised controlled trial (RCT) designed to test the efficacy of the selected BEP supplement(s) during pregnancy and lactation on pregnancy and child health outcomes in the same population (ClinicalTrials.gov Identifier: NCT03668977).

| Study setting
This study was conducted in Sarlahi, a rural district located in the southern plains of Nepal. The study population in Sarlahi district meets the definition of an undernourished population based on the nutritional status of >28,000 pregnancies enroled in a previous large trial conducted in 2012-2017 (ClinicalTrials.gov, NCT01177111).
Early pregnancy mean BMI among the study participants was 19.1 kg/m 2 and 37% were underweight, with a BMI < 18.5 BMI (data not published). The incidence of LBW and SGA was 29.4% and 46.8%, respectively, in the same trial (data not published).
The typical daily diet in Sarlahi like in most parts of Nepal consists of rice (main staple), lentils and some seasonal vegetable dish with a pickle dish consumed twice daily by most people. Previous research in this study population showed that rice intake can be reduced during pregnancy, which could be attributed to an aversion to food or lack of appetite while for most protein and micronutrientrich foods, the majority reported eating the same quantities during pregnancy (Christian et al., 2006). Another study found that multiple micronutrient deficiencies are common during early pregnancy in this population (Jiang et al., 2005).
Recruitment for this first phase of the formative research was conducted in Pidari and Pipariya Village Development Committee (VDC; previous lowest administrative structure which was dissolved in March 2017 and replaced by rural municipalities) that fall under Haripur and Kabilasi municipalities. ('Municipality' in this context is an administrative term, but actually is comprises of a number of different VDCs). The study area within each municipality was selected because it was of moderate size (i.e., not too big or small a municipality in terms of geographical size), centrally located (i.e. middle of the district) and representative of the study district in terms of ethnicity, caste and religion. The two VDCs that were selected in those municipalities have both Hindus and Muslims representative of the study district which is a majority Hindu population and about 8% Muslim. The population in these areas, as opposed to the northern areas of the district, is more rural and consists mostly of the Madhesi (people from the Terai plains) ethnicity, which makes up the majority of Terai as opposed to the Pahadis (people from the hills).
The ethnicity, caste and religion of our formative research population are generalisable to the Terai region as the sample group is similar to that in the Terai which is predominantly Madeshi ethnic group of Hindu religion who live in rural areas. We sampled more Muslims in our study than the current distribution in the population so as to get more in-depth data on this minority group in the qualitative interviews since they would be included in the main trial.
The implementation of the data collection and field work was

| Recruitment and inclusion criteria
The inclusion criteria for enrolment of women into this study were to be married, pregnant and between 15 and 40 years of age. As per the Nepal Health Research Council research ethical requirement, a married woman under the age of 18 years is considered a minor and so was recruited and enroled in this study only after obtaining signed informed consent from the husband or guardian. Women were excluded if they had a known allergy to soy, dairy products, eggs, gluten or nuts. All women in the study area were recruited from the community; those who met the inclusion criteria and did not fit the exclusion criteria were added to the recruitment list which comprised 82 pregnant women. A purposive sample of 40 pregnant women was selected based on their age and gestational age and enroled into the study after obtaining informed consent. The first author (TPL) helped purposively sample the participants with consultation with the NNIPS senior field team staffs.

| Study design and procedures
This formative research used a mixed-methods approach combining qualitative and quantitative methods for data collection. Each participant participated in two consecutive days of data collection: the first day included individual tasting of six "sweet" supplements, and the second day included the tasting of five savoury BEP supplements followed by FGDs.
On the first day, the interviewer went to the woman's home and collected basic socio-demographic information from the participant. After that, the participant was asked to consume test portions of each of the six sweet BEP supplements. These were offered in a randomised sequence to avoid possible bias due to order of presentation. The test portions for each supplement were pre-portioned by the field staff to be 25% of the weight of a full daily portion. The women were given up to 30 min to consume as much of each of the test portions as they could/wanted to or until they said they would not eat any more. After the consumption of the test portions of each BEP supplement, a structured questionnaire was used to ask the participant to rate the characteristics of each BEP (1 = Dislike it very much to 7 = Like it very much). In addition, data were collected on willingness to consume these supplements every day during pregnancy and 6 months postpartum for up to a total of 12 months using a 5-point Likert scale (1=Definitely would not eat every day to 5=Definitely would eat every day). Information as to whether the full portion size of each supplement was hypothetically the right amount, too much or too little for a daily snack portion was also collected. Data regarding the extent to which the product was 'easy to prepare and consume' and 'easy to consume in between meals as a snack' were collected separately using a 7-point Likert scale (1 = Very difficult to 7 = Very easy). Women were also asked if they perceived the supplement as a food, a medicine or as both a food and medicine by directly asking her opinion given the three options. This question was in Likert-scale format but was found to be very confusing for the participants during the pre-test phase and so it was decided to keep it simpler. At the end of the first day, each participant was asked to rank the six sweet products from 6 (Most preferable/acceptable) to 1 (Least preferable/acceptable) according to each of the organoleptic properties. On the second day, each participant was brought to the NNIPS field office for tasting the test portions of the remaining five savoury products in a randomised sequence. The same structured questionnaire was administered on a one-to-one basis to assess each supplement's acceptability and the participant's willingness to use it in the future, followed by a ranking of the five savoury products on their organoleptic properties. An overall ranking of the top three most preferred out of the 11 BEP supplements was finally collected from each participant.
Complementary qualitative data were also collected using FGDs.
Each of the 40 women was assigned to one of five FGD groups (A-E); the participants were divided into groups to promote homogeneity within each group in terms of age group (≤20 years and >21 (Kumar, 1987); younger women may hesitate to speak freely in a group with older individuals given the South Asian norms of showing respect to elders by not speaking against them. The FGDs aimed to better understand factors influencing overall acceptability and preferences of flavour profiles, as well as sharing dynamics, local food practices and potential utilization of each of the 11 supplements. Focus groups generated data to better understand social norms. An additional ranking exercise was included in the FGDs to elicit further narratives around characteristics affecting the potential use of the products and how those characteristics related to each other. Participants were then asked to discuss and reach consensus as a group on their top three supplements. Figure 1 illustrates the mixed-methods approach used to triangulate the data of this study.
Data collection was conducted over three weeks from 16 July to

| Data analysis
Participant characteristics, including socio-demographic and pregnancy characteristics, were summarised using means (SD) for continuous mea- The results of the ranking exercise were summarised by each type of product grouping (sweet and savoury) and overall 'Top 3'. In each ranking exercise, a supplement was assigned the highest score for the most preferred product and lowest score for the least preferred product. For the overall likeability ranking of 'top 3' BEP supplements out of the 11 supplements, a product was awarded three points if it was ranked first, two points if ranked second, one point if it was ranked third and zero points if it was not included in the top 3. The sum of each score for the 11 BEP supplements was then ranked using the sum of ranks method in Excel.
Preliminary iterative analysis of the qualitative data was conducted throughout the data collection process. In conclusion of the data collection, full analysis of the qualitative data was conducted using thematic analysis (Braun & Clarke, 2006). Dominant themes were identified through the systematic review of FGDs and field notes and a thematic framework was iteratively developed. Salient concepts were coded, and their occurrence and recurrence were labelled. Basic themes were deductively generated. These initial themes were reviewed and emergent codes and sub-codes were iteratively refined throughout the process.

| RESULTS
The mean (SD) age of study participants was 22.7 (3.7) years and the ages ranged from 16 to 30 years. The religion of the majority of the participants was Hindu (72.5%) and their ethnicity was Madeshi (i.e., southern plains; 97.5%). The socio-demographic and pregnancy characteristics of the study participants are presented in Table 2. Table 3 shows the results of the hedonic scale responses rating the sensory properties (colour, taste, smell, texture and overall) of the 11 BEP supplements. The sweet LNS, sweet vanilla drink, savoury LNS and savoury seasoned pillows were rated highly, with a median response of '7 = Like very much' on all sensory properties. The taste, smell and/or texture of the sweet mango bar, sweet cocoa drink, savoury masala bar and savoury curry biscuit received lower ratings;

| Hedonic properties
the lower quartile (Q1) of the interquartile range for the latter BEP supplements show several scores between 1 (dislike very much) and 3 (dislike slightly; Table 3). The distribution of the responses on the 7-point hedonic scale showed that sweet LNS and savoury seasoned pillows were liked very much by the vast majority of the participants (75% and 70%, respectively). In contrast, 30% and 35% of the participants reported disliking the sweet cocoa drink and savoury curry biscuits very much, respectively (Table 3)  Participants likened the sweet LNS to a number of favourite local foods, including 'Halwa' a sweet pudding, 'Satu', a cereal-based snack, and a variety of commercial products. Women consistently liked the savoury seasoned pillows for colour and for the taste, which many described as 'a little salty and a little sweet' but also 'a little spicy'.
One response from a woman in FGD group A was illustrative: 'Yes, its sour and spicy type, that's why they would eat more during pregnancy'.
The seasoned pillows were positively associated with a number of other familiar tasting foods, particularly Indian crisps and snacks. The vanilla drink also had positive reviews during the FGDs, where most of the participants liked its colour, smell and taste. One person in FGD group B commented that the smell resembled that of ice cream, while the taste was positively likened to peanut 'satu' and baby food or malted milk powders. In FGD group C, the vanilla drink was also likened to a powdered protein drink for pregnancy and lactation available in the local market. The vanilla biscuit was liked by most of the women in the FGDs, although some participants in FGD group C did not like its taste and smell and suggested it tasted like medicine.
The FGDs also highlighted the reasons for not liking certain properties of the BEP supplements. For instance, some participants in FGD group B disliked the savoury masala bar for its taste and smell. The texture was also described negatively as something that felt 'rough' and 'sticks to your teeth'. The savoury curry biscuit was also disliked for its colour, taste and texture where participants in group B made specific and negative reference to individual flavours in the product, such as cumin, pepper, fenugreek, turmeric and 'jwano' (thyme seed), and commented that it was too salty and tasted like medicine as it was bitter to taste. A few women liked the cocoa drink but most did not, because of its colour and bitter taste, which was compared to medicine. Some of the most negative comments on the cocoa drink came from participants in FGD group B: 'It tastes bitter and it's black'; 'Just looking at the colour might make people feel like vomiting. It looks like sewage water'. Participants disliked the unseasoned pillows because of its bland taste, although they found it similar to popcorn in terms of taste and smell.

| Use of products during pregnancy
We explored perceptions of supplement use during pregnancy by asking, for each BEP supplement, how easy it would be to prepare and use and how easy it would be to eat as a snack in between meals.
The responses to both questions were positive with the median response being '6 = Easy' or '7 = Very easy' for all 11 supplements (Table 4). There was little variability in the response to the question on "willingness to use the supplement daily for up to 12 months if provided for free', with the median response for all 11 BEP supplements being '5 = Definitely would eat every day'. The median response to perceived likelihood of sharing the supplements with others was '1 = Definitely would not share' (Table 4). Except for the cocoa and vanilla drink supplements, the majority of participants considered the supplements to be a food rather than a medicine as shown in Table 4.
For each supplement type, the FGD facilitator probed the reasons why women would or would not use the supplements during the pregnancy period. Most of the participants agreed that they would eat the supplements every day during pregnancy as it would benefit the mother and baby, and they associated it with giving energy to the mother and baby. A participant in FGD group D stated, 'If you eat this, nothing will happen to the mother and child, they won't be weak, it will be good'. In FGD group C, women expressed the intention to eat the product every day but stated that 'Sometimes it can be missed but will eat…' and that 'It will be missed during fasting period and all otherwise it can be eaten regularly'. A few women had a strong aversion to the smell or taste of certain supplements like the mango bar, cocoa drink, vanilla biscuit, curry biscuit, and masala bar; they said the product(s) made them feel like vomiting and they would not be able to eat them every day.
Cost was raised as a potential obstacle to eating a supplement every day: 'If it is provided for free you can eat it [for 12 months] but cannot afford to buy it' (participant in FGD group A). When asked about convenience of eating the supplements, women did not identify any difficulties except for potential issues eating when others are around. One woman in group A said 'How to eat in front of many people, it does not look good, one person is eating and rest of others are looking'. It was also suggested that it could be difficult to eat the supplements in front of children, who might expect them to share it.
In two of the FGD groups (A and B), the participants raised concerns about being limited to the use of one product for the duration of pregnancy. The majority of participants in both groups agreed that they could eat supplements throughout pregnancy, although it was highlighted that alternating between more than one supplement would be preferable. One woman in group B said 'eating the same food every day one will feel like vomiting ('wak wak')…look, people just don't eat rice and lentils every day, they sometimes eat vegetables and rice, don't they? It is possible to eat for one week [then] alternate'. It was suggested by these women that 'desires' would not be fulfilled if the same products were eaten daily, and there was general agreement that products should be alternated weekly. Table 5 presents the results of the (1) individual product ranking activity based on overall preference, (2) group product ranking activity and (3) the mean individual product acceptability score for the top five products along any of those three metrics. According to the individual 'top 3' ranking on overall preference and the mean score for product acceptability, the top two products were the sweet LNS and the seasoned Supplement is convenient to eat easy to prepare and use 7 (7, 7) 6 (5, 7) 7 (6, 7) 7 (6, 7) 6 (5.5, 7) 7 (6, 7) 7 (6, 7) 7 (6, 7) 7 (5, 7) 7 (7, 7) 7 (6, 7)

(1, 4)
Consider product to be a medicine or food or both or neither, n (%) pillows. The FGD group ranking indicated the sweet LNS as the most preferred, followed by the vanilla drink, and a tie between the seasoned pillows and vanilla biscuit for the third most preferred.
The three least preferred BEP supplements based on the individual ranking of the 'top 3' were the unseasoned pillows, curry biscuit and cocoa drink with a sum of ranks score of 1, 6 and 6, respectively. were responses most common among those with low adherence (Harding et al., 2014). Another acceptability study of a peanut-based ready-to-use therapeutic food given to malnourished PLW in Bangladesh reported that, despite a perceived therapeutic benefit, almost 80% of the participants found it to be unacceptable due to its undesirable taste and smell (Ali et al., 2015). Sensory/organoleptic attributes of the supplements were central to acceptability of similar small-quantity LNS given to PLW in two randomised trials in Ghana and Malawi (Klevor et al., 2016) and an acceptability study in rural Niger (Isanaka et al., 2019). In a trial among pregnant women in Mexico, micronutrient powders and tablets were preferred over fortified food (Nutrivida) because the participants disliked certain sensory properties of the fortified food (i.e., smell, taste and texture; Young et al., 2010).

| DISCUSSION
The efficacy of a complementary feeding intervention depends on sustained consumption of the products (i.e., adherence). During pregnancy, women are more likely to have strong preferences for and aversions to certain smells and tastes (sweet vs. savoury), in addition to nausea and vomiting common in many pregnancies (Bowen, 1992). This study found that some pregnant women preferred sweet products and some savoury, so having at least one supplement of each kind would be likely to increase adherence among a group of pregnant women. The qualitative findings also highlighted the need for an option to choose different types of supplements on a weekly basis, especially when having to take the supplement regularly for a long period of time (i.e., daily use for 12 months starting from second trimester of pregnancy through the first 6 months of lactation). Very few efficacy trials of BEP supplements have provided an option to choose between two or more supplements; this could be an important strength in future intervention trials to ensure adequate long-term adherence.
Similar to other acceptability studies of food supplements for PLW, one of the motivating factors for acceptance and possible adherence to the BEP supplements in this study was their perceived positive health benefit for the mother and the unborn baby (Adu-Afarwuah et al., 2011;Clermont et al., 2018;Harding et al., 2014;Klevor et al., 2016;Mridha et al., 2012). Responses to questions about the likelihood to share or expectations to share the supplements with others in the household in a hypothetical situation were mixed; some women said they would have to share, especially with children, and others reported they would not. Sharing behaviour was further explored in the home-tasting pilot trial (phase 2) that showed some sharing in both supplement type groups with an average sharing of no more than one day in the 8-week testing period (Lama et al., 2021). In the pilot trial, we tried to ensure low sharing of supplements by advising the pregnant women that the supplements were for pregnant women only and also labelled the supplements with a picture of pregnant and lactating women. The majority of women who shared, reported sharing the supplement with their child or children in the household in the first week of the pilot trial (Lama et al., 2021). In-depth interviews with the women and family members, indicated that referring to the supplements as medicine for pregnant women or eating the supplement when alone helped dissuade children from asking to share (Lama et al., 2021). Results of other home-tasting pilot trials of maternal nutritional supplements support our findings that some sharing is expected. This has been seen especially in the beginning of trials, to respond to the curiosity of family or friends (Klevor et al., 2016) and particularly small children (Clermont et al., 2018). Sharing of food supplements among household members has been identified as a potential barrier to optimal supplement adherence (Beckett et al., 2016;Kodish et al., 2017). The majority of our study population identified the BEP supplements as a 'food' or 'both food and medicine', which is consistent with other food supplementation studies (Adu-Afarwuah et al., 2011;Clermont et al., 2018;Mridha et al., 2012). A trial in Niger of three nutritional supplements found that women in the LNS arm were more likely to over-consume the product because they associated it with food, compared to women in the other two arms who were given either a Product acceptability (mean score on 7-point scale) 2 (6.3) 1 (6.4) 5 (5.9) 3 (6.2) 4 (6.0) multi micronutrient supplement or iron/folic-acid supplement (Clermont et al., 2018). This should be further explored in the larger efficacy trial. Similar formative research to understand PLW acceptability of BEP supplements was also implemented in Burkina Faso before a similar home-tasting pilot trial also designed to inform a randomised trial to test the efficacy of BEP supplements on newborn and infant health and growth outcomes . The formative research in Burkina Faso was also conducted among 40 pregnant women and tested 12 different products, out of which 8 were the same products used in our study. The four different products in the Burkina Faso study were (i) fermented drink, (ii) tomato and onion bar, (iii) tomato and onion biscuit and (iv) chicken soup.
Several of the flavours were developed specifically to evoke familiar flavours from the Burkinabè diet, such as the fermented drink. In contrast to our study, the pregnant women in the Burkina Faso site preferred products with familiar flavours that are perceived as sweet rather than savoury. The sweet LNS and sweet vanilla biscuit were the top two products and none of the savoury products was ranked in the top five product preferences .
The hedonic test and ranking exercise held over two days allowed us to quantify the responses on the organoleptic properties, rank the top three supplements on those properties and understand acceptability from multiple angles and perspectives. The FGD done at the end of the test meals provided further insight into the reasons for the high or low acceptance of the various supplements. By using both quantitative and qualitative data collection methods on the same topic, our study design included methodological triangulation. However, we did not use different study was uniquely positioned to test 11 prototypes of BEP supplements that were developed for PLW before an efficacy trial. This gave us the opportunity to identify the most acceptable BEP supplement(s) for use in the home-tasting pilot trial (phase 2) which would then aim to assess midterm adherence for the shortlisted BEP supplements up to 8 weeks.
This study has some limitations. First, the test-meal observation was conducted only once and so was subject to reactive behaviours (Gittelsohn et al., 1997); this could have been reduced through repeated observation of the test meals on consecutive days as done in the study in Niger (Isanaka et al., 2019). Second, social desirability bias may have resulted in underreporting of negative responses to attributes of the BEP supplements (Fisher, 1993). The Likert scores on organoleptic properties varied only slightly between products, with predominantly positive median scores in the 6 (Liked moderately) to 7 (Liked very much) range.
This may reflect the limitations in using a Likert scale to assess supplement acceptability in a cultural context where people are unfamiliar with the Likert scales and may be unwilling to provide negative feedback (Flaskerud, 2012; J. W. Lee et al., 2002). The use of mixed methods to triangulate the findings using hedonic scales, ranking exercises, and FGDs aimed to mitigate this bias to some extent. In addition, some products did appear to be disliked by at least some fraction of the participants relative to other products, allowing for differentiation of products in terms of preferences. Certain questions were more hypothetical questions (e.g., would you consume these supplements every day during pregnancy and six months postpartum?) making it difficult to answer and could have resulted in some bias. However, the second phase of the formative research with the 8-week home-tasting trial will assess longer-term use and acceptability with the shortlisted BPE supplements. Another major limitation to this study was that since we grouped the FGDs by caste/ religion and age resulting in five strata (Table S2), and each stratum consisted of one FGD only due to small sample size of the study (N = 40), the authors cannot confirm that data saturation of key themes among all strata was reached. Finally, the second-day test-meal observation and the FGDs were conducted at the office premises maintaining privacy and confidentiality but the change in interview location to an outside of home setting could potentially have influenced the results. However, this cannot be ascertained from the data.

| CONCLUSION
This study assessed the acceptability of 11 BEP supplements among pregnant women in Nepal. The fortified BEP supplements were developed for this study specifically to meet the nutritional needs of pregnant and lactating women. Understanding the acceptability of such food supplements before their use among PLW is vital to ensure regular consumption. We conclude that the sweet LNS and savoury seasoned pillows were the most acceptable to pregnant women in this rural Nepali population.